1. Field of the Invention
The present invention relates to a service verifying system for providing a plurality of services, an authentication requesting terminal to be authenticated by the service verifying system to utilize a service provided by the service verifying system, a service utilizing terminal for utilizing another service provided by the service verifying system on the basis of the result of the authentication of the authentication requesting terminal, and a service providing method.
2. Description of the Related Art
There are conventionally known systems for providing services for cell phones and PHSs in mobile communications and others. Each user needs to have a contract with a company providing services in order to utilize such services. Many of companies providing services provide services for only users having a contract for utilization of services (qualified users), but do not provide services for users without a contract. For this reason, it is necessary to establish a scheme for letting only the qualified users utilize the services, and schemes of this type have already been substantialized heretofore.
The existing service verifying systems for providing services employ a control system of managing customer information of qualified users, authenticating whether a user requesting utilization of a service is a qualified user, using the customer information, and permitting the utilization of the service only when the result of the authentication is affirmative. It is necessary to build up such a system, in order to let only the qualified users utilize the services.    [Nonpatent Document 1] Bruce Schneier, “APPLIED CRYPTOGRAPHY,” John Wiley & Sons, Inc., 1996, pp. 52-56    [Nonpatent Document 2] “NTT Docomo Technical Journal Vol. 9, No. 4,” The Telecommunications Association, January 2002, pp. 34-43    [Nonpatent Document 3] Keiji Tachikawa, “W-CDMA MOBILE COMMUNICATIONS SYSTEM,” John Wiley & Sons, Ltd, 2002, pp. 345-356